thrid Posted April 19, 2021 Share #1 Posted April 19, 2021 (edited) Advertisement (gone after registration) Has anyone else attempted to determine the ISO equivalent of the M10 to a standard incident light meter? Here is how I came up with these numbers. I filled the frame with a large Kodak gray card using live view on the M10 and took a reading. Then I took an incident reading with my Sekonic and compared the two. This test was conducted on a sunny summer day around noon, with a clear blue sky to remove the weather as a variable. Using this method I came up with the following: M10 SEKONIC.(ISO) 200. 0125 400. 0250 800. 0500 1250. 0800 1600. 1000 3200. 2000 6400. 4000 Overall the two seem a match in exposing the gray card. Has anyone else given this a try? Edited April 19, 2021 by thrid typo 1 Link to post Share on other sites More sharing options...
Advertisement Posted April 19, 2021 Posted April 19, 2021 Hi thrid, Take a look here M10 with light meter. I'm sure you'll find what you were looking for!
Narsuitus Posted April 19, 2021 Share #2 Posted April 19, 2021 When I first started using my M10, I noticed that compared to my Gossen incident/reflective light meter, the light meter in my other digital cameras, and the Sunny 16 Guideline, my M10 needed a +1 exposure compensation to produce matching images. Link to post Share on other sites More sharing options...
farnz Posted April 19, 2021 Share #3 Posted April 19, 2021 7 hours ago, thrid said: I filled the frame with a large Kodak gray card using live view on the M10 and took a reading. Then I took an incident reading with my Sekonic and compared the two. Immediately there's a discrepancy because you're using an incident reading on the Sekonic but the M10's light meter measures light reflected off the grey and white stripes on the shutter blades (unless you're using it in LiveView, which you didn't mention). Pete. 1 1 Link to post Share on other sites More sharing options...
thrid Posted April 20, 2021 Author Share #4 Posted April 20, 2021 Pete, you're dead on right. It's taking a reflected reading off the gray shutter curtain.... Oops... didn't think that one all the way through Let me repeat my readings with a spot meter. 2 Link to post Share on other sites More sharing options...
david strachan Posted April 20, 2021 Share #5 Posted April 20, 2021 It should still be the same standard though. I realise the M digitals take the exposure off the sensor, or originally off the striped shutters. I've done the testing between many cameras and many lightmeters, and particularly the sunny blue sky opposite the sun in Adelaide Australia. I've had this discussion before, and got tired of the "arguments". But i still think there should be a set standard for mid grey exposure, for all camera standards, not just a moveable goalpost by manufacturers...who can then claim higher ASA, which should be ISO but isn't, etc. Link to post Share on other sites More sharing options...
andyturk Posted April 20, 2021 Share #6 Posted April 20, 2021 I meter off my pasty, pink hand and then open up a stop. YMMV. 1 Link to post Share on other sites More sharing options...
ejk64 Posted April 20, 2021 Share #7 Posted April 20, 2021 (edited) Advertisement (gone after registration) hello , 6 days ago with a blue sky I wanted to test my light-meter with the f16 rule : f16 + 200 iso gives 1/250, which is correct. here are the 2 dng photos opened with c1 edition 21: the first without processing (the blue sky is too dark) and the second with the automatic correction (the blue sky is more truthful) . in summary it is possible that I must permanently use a correction of + 0.75il during my shots ... Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! leica m10-p "reporter" + summicron-m35/2 asph Edited April 20, 2021 by ejk64 Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! leica m10-p "reporter" + summicron-m35/2 asph ' data-webShareUrl='https://www.l-camera-forum.com/topic/320096-m10-with-light-meter/?do=findComment&comment=4184977'>More sharing options...
fisheess Posted April 20, 2021 Share #8 Posted April 20, 2021 59 minutes ago, ejk64 said: hello , 6 days ago with a blue sky I wanted to test my light-meter with the f16 rule : f16 + 200 iso gives 1/250, which is correct. here are the 2 dng photos opened with c1 edition 21: the first without processing (the blue sky is too dark) and the second with the automatic correction (the blue sky is more truthful) . in summary it is possible that I must permanently use a correction of + 0.75il during my shots ... Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! leica m10-p "reporter" + summicron-m35/2 asph If your focus point was in the center of the frame, then the light meter in camera metered mostly on the white wall. There is no surprise here that the whole picture is underexposed. 1 Link to post Share on other sites More sharing options...
jaapv Posted April 20, 2021 Share #9 Posted April 20, 2021 5 hours ago, david strachan said: It should still be the same standard though. I realise the M digitals take the exposure off the sensor, or originally off the striped shutters. I've done the testing between many cameras and many lightmeters, and particularly the sunny blue sky opposite the sun in Adelaide Australia. I've had this discussion before, and got tired of the "arguments". But i still think there should be a set standard for mid grey exposure, for all camera standards, not just a moveable goalpost by manufacturers...who can then claim higher ASA, which should be ISO but isn't, etc. ISO As digital ISO equivalent value is set by the amplification in the camera and film values are determined by density measuring of film, this appears to by quite a challenge. 3 Link to post Share on other sites More sharing options...
Erato Posted April 20, 2021 Share #10 Posted April 20, 2021 8 minutes ago, jaapv said: As digital ISO equivalent value is set by the amplification in the camera and film values are determined by density measuring of film, this appears to by quite a challenge. The current understanding is pretty close even I comparing with Gossen Starlite II 1° spot meter against "Automative" mode on my M10 Monochrom. And the good thing is Dynamic Range tolerance of M10M is good enough to retrieve every bit of the photons within two to three stops while underexposed. And the M10-P may be similar, but I'd remind myself to keep it underexposure on every shot indeed. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/320096-m10-with-light-meter/?do=findComment&comment=4185028'>More sharing options...
jaapv Posted April 20, 2021 Share #11 Posted April 20, 2021 But there is an essential difference between a sensor and negative film: With a sensor you need to protect the highlights and recover the shadows, and with film it is the other way around - and this affects your exposure bias. The main reason that I prefer an EVF over an OVF is that I can watch the histogram real time and leave all these exposure measuring concerns behind me. 2 Link to post Share on other sites More sharing options...
Erato Posted April 20, 2021 Share #12 Posted April 20, 2021 I always use a light meter to secured an accurate exposure while dealing with reversal films (analog) such as RAP, RDP III, or Ektachrome 25/64/E100(S) or else. That was a good practice for me to choose the sweet spot for relatively accurate exposure while dealing with digitalized gears. Link to post Share on other sites More sharing options...
thrid Posted May 7, 2021 Author Share #13 Posted May 7, 2021 (edited) I went out and redid my test. Here are the results What I find interesting is the difference between setting the shutter speed manually and aperture priority. But that could be do to a variety of variables... My gray card is a few years old, but has been stored in darkness, so I do not believe that it is too far off, if it has deteriorated. Kodak gray card, Sekonic 508 Cine, Leica M10 ASA STOP M10 MANUAL M10 APERTURE Sekonic SPOT Sekonic INCIDENT 100 f16 1/90 1/125 1/125 1/125 200 f16 1/125 1/250 1/250 1/250 400 f16 1/360 1/500 1/500 1/500 800 f16 1/750 1/1000 1/1000 1/1000 1250 f16 1/1000 1/1500 1/1500 1/1500 1600 f16 1/1500 1/2000 1/2000 1/2000 3200 f16 1/3000 1/4000 1/4000 1/4000 6400 f16 Out of range Out of range 1/8000 1/8000 Regardless of the results I say that with digital you protect the highlights and with film the shadows. Edited May 7, 2021 by thrid 1 Link to post Share on other sites More sharing options...
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